1. Field of the Invention
The invention relates to a connector with a twisting connection preventing means and to a method for assembling such a connector.
2. Description of the Related Art
Some connectors have a female connector housing that is fit into a receptacle of a male connector housing for connection. The connectors often have a twisting connection preventing means for preventing the male and female housings from being connected in a rotationally improper orientation. For example, a rib may project from the outer circumferential surface of the female housing and may extend along connecting directions of the two housings. A guide groove may be formed in the inner circumferential surface of the receptacle of the male housing for closely engaging the rib. Thus, the female housing can be fit straight into the receptacle by engaging the rib with the guide groove. The rib is positioned at the front end of the female housing to prevent a twisting connection at an early stage of the connection process.
Connectors of this type also may have guiding surfaces at the opening edge of the receptacle of the male connector housing and at the opening edge of the guide groove to correct the misalignment of the two connectors and to achieve a smooth connection. Large guiding surfaces are formed to correct the misalignment in connectors in which the male and female housings are automatically positioned, such as in self-aligning connectors.
The rib of the above-described connector is fit into the guide groove at the same time the female connector housing is fit into the receptacle. Thus, as shown in FIG. 8, a guiding surface 3 at the opening edge of a guide groove 2 for the insertion of a rib 1 needs to be substantially as large as a guiding surface 5 at the inner opening edge of the receptacle 4 to effectively correct the misalignment. This makes the outer shape of the receptacle 4 larger, and hence makes the connector larger.
The present invention was developed in view of the above problem, and an object thereof is to further miniaturize a connector provided with a twisting connection preventing means.
The invention is directed to connector with first and second housings. The first housing has a receptacle and the second housing is configured to fit into the receptacle. At least one rib is formed on the outer surface of the second housing and extends along the connecting direction of two housings. At least one guide groove is formed in the inner surface of the receptacle for guiding the rib therein, and at least one guiding surface is formed at opening edges of the inner surface of the receptacle and/or the guide groove. The front end of the rib is retracted from the front end of the second housing by a retracted distance that is longer than a dimension along the connecting direction over which the guiding surface is formed on the receptacle.
The connectors may be misaligned in the process of fitting the second housing into the receptacle of the first housing. However, one edge at the front of the second housing first contacts the guiding surface at the opening edge of the receptacle. At this stage, the front end of the rib has not yet contacted the guiding surface on the guide groove. The second housing then is fit further so that the edge at the front end of the second housing slides on the guiding surface, thereby correcting the misalignment and guiding the second housing into the receptacle. The rib enters the guide groove after the guiding of the second housing is completed. The front end of the rib contacts the guiding surface on the guide groove and slides thereon to correct the inclination even if the second housing is inclined slightly from its proper posture. Thus, the rib is guided into the guide groove. In this way, the second housing can be fit straight into the receptacle without twisting.
As described above, the rib and the guide groove already are positioned with respect to each other when the second housing is fit into the receptacle. Thus, the guiding surface for the rib needs not be as large as the guiding surface for the second housing. Accordingly, the opening edge of the guide groove and the entire receptacle can be smaller. This consequently enables the miniaturization of the connector.
A terminal preferably is accommodated in the first connector so that a portion of the terminal projects into the receptacle. The retracted dimension preferably is shorter than a distance between the front end of the receptacle and the leading end of the terminal projecting into the receptacle. Thus, the front end of the second housing cannot contact and bend the leading end of the terminal before the rib is guided into the guide groove.
The rib(s) preferably are arranged to prevent an improper connection of the housings.
The guide groove preferably comprises at least one auxiliary guiding surface for contacting the corresponding rib to guide the connection of the housings.
The guiding surface is wider to correct the misalignment of the second housing with respect to the receptacle over a wider area. Thus, the auxiliary guiding surface is smaller than the guiding surface.
The guide groove may be formed by bulging out a portion of the receptacle.
The engaging edge of the second housing and/or the rib may have a slanted or rounded guiding portion.
The invention also relates to a method of assembling, mounting or connecting a connector that has first and second housings. The method comprises fitting the second housing into a receptacle in the first housing. The connection is guided by at least one guiding surface formed on at least part of the opening edges of the inner surface of the receptacle. The method continues by engaging at least one rib formed substantially along the connecting direction of housings and on the outer surface of the second housing with at least one guide groove formed in the inner surface of the receptacle after the second housing is fit into the receptacle by a fitting distance. The fitting distance is longer than a dimension along the connecting direction over which the guiding surface is formed on or at the receptacle.
At least one terminal may be accommodated in the first connector so that a portion of the terminal projects into the receptacle. The fitting distance is shorter than a distance between the front end of the receptacle and the leading end of the terminal that projects into the receptacle.
Preferably, an improper connection of the housings is prevented by the rib(s).
The connection of the connector housings preferably is guided further by contacting at least one auxiliary guiding surface of the guide groove with the corresponding rib.
Misalignment of the second housing with respect to the receptacle preferably is corrected over a wider area by the wider guiding surface. The guiding surface preferably is smaller than the guiding surface.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.